Cup brush



April 23, 1957 B. E NELSON CUP BRUSH Filed Oct. 26, 1953 lllllllllll/ v INVENTOR. 3300/6 5. NfL60/V BY m ,4 A

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United States PQEQ O 2,789,303 CUP BRUSH Brooks E. Nelson, Chagrin Falls, Ohio, assignor to The Osborn Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application October 26, 1953, Serial No. 388,335 6 Claims. (Cl. 15-180) This invention relates as indicated to a cup brush, and more particularly to a rotary brush of the twisted tuft type adapted to be mounted on a spindle or the like and driven at relatively high speeds. Reference may be had to Bickel et al. Patent No. 2,062,047 and to Peterson Patent No. 2,480,877 for examples of brushes of this general type.

Rotary brushes and more particularly cup brushes of the coil knot or twisted tuft type in which the brush material comprises a series of twisted tufts formed by doubling and then twisting a bundle of stranded brush material, usually wire, serve a wide variety of purposes and are commonly employed when a relatively harsh brushing action is desired as for the removal of excess weld metal, mill scale, etc. Inasmuch as the twisted tufts extend generally parallel to the axis of the tool, they are especially subject to the action of centrifugal force in use, and there is a resultant tendency for the brush to become distorted from its original shape. This tendency is, of course, accentuated when the brush is pressed forcibly against the work. When the bristle tufts are held within a cup having side walls which flare outwardly at a considerable angle this difficulty is minimized since the tufts likewise have an initial flare but, on the other hand, the brushing action then obtained is not as effective as desired for certain types of work. A straight-sided cup would accordingly often be preferable, but has not proven satisfactory in the past for the reason that the resultant brush quickly got out of balance. These brushes ordinarily comprise an inner and outer ring of tufts, and under the influence of. centrifugal force tufts of the inner series would tend to swing radially outwardly with pairs of such tufts often forcing themselves in between tufts of the outer series, thereby producing an irregular brushing surface and putting the tool out of balance. As in the case of any high speed rotary tool, proper balance is, of course, essential, since otherwise a violent wobbling effect will be obtained.

It is accordingly a principal object of my invention to provide a cup brush in which the brush material extends generally parallel to the axis of rotation of the tool and in which the inner portion of the brush material is constrained from interposing itself into the outer portion of such material to produce unbalance and uneven brushing action. I

Another object is to provide a novel cup brush wherein the various elements are assembled together in a simple but strong manner to enable the brush material to resist both outward flaring action under the influence of centrifugal force and also pressure when the tool is held forcibly against the work.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed draw ing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle ofthe invention may be employed.

In said annexed drawing: Fig. l is a diametrical transverse section through a brush embodying my invention;

Fig. 2 is a perspective view of an inner cup element employed in the assembly; and

Fig. 3 is a plan view of an annular disc or washer to and a bundle of brush bristle material (ordinarily wire) 7 is passedthrough each hole and twisted upon itself to form the twisted tufts 4. The base of cup 1 is bulged or deformed at 5 to provide a shallow annular channel adapted to receive the rebent portions of such tufts when ring 2 is seated therein as shown in Fig. 1.

A second inner cup 6 (Fig. 2) in the form of a thin sheet metal stamping is next seated within cup 1, the sides of such cup 6 being dimensioned closely to engage the inner sides of the row of tufts 4 and having an inner opening 7 of the same diameter as the inner opening 8 of ring 2 similarly to fit the central cylindrical portion 9 of cup 1. It will thus be seen that the outer row of tufts 4 is in efiect retained within a rather deep annular channel defined by the walls of cups 1 and 6 respectively. The side wall of cup 6 is dimensioned to extend to a point substantially equal to that of the side wall of cup 1 and will desirably slope slightly radially outwardly. The outer lip 10 of cup 1 may also desirably be slightly fiared, but the side of the cup itself is preferably substantially parallel to the axis of rotation of the tool.

A small spacer washer 11 is next inserted followed by ring 12 generally similar to ring 2 but of a smaller diameter to fit within cup 6 as shown and provided with a similar series of twisted bristle tufts 13. A slightly dished washer 14 is then installed adapted to engage the inner side of the ring of tufts 13 to hold the same in the general position illustrated in Fig. 1. Of course, when the tool is mounted upon a spindle and rapidly rotated, such tufts tend to swing radially outwardly. The inner end portion 15 of the inner cylindrical hub 9 of cup 1 may now be upset as shown to clamp the above-described components together as a permanent assembly.

When the tool is placed in operation, it will be seen that the outer ring of tufts 4, being retained within the relatively deep annular channel defined between cups 1 and 6, will not tend to flare outwardly unduly under the action of centrifugal force. ring, of tufts 13 is supported by cup 6 against like outwardly flaring movement and even more important,.two

or more such tufts 13 are prevented from becoming interposed between two adjacent tufts 4 and throwing the tool out of balance. I have accordingly provided a high speed rotary tool utilizing twisted tuft brush mate- As shown in Fig. l, the inner and outer series of tufts will generally extend an equal distance from the cupshaped holder, and the lip of the inner cup will encircle the inner series of tufts in the general region defined by the lip of such holder. Such inner cup may, however,

Patented Apr. 23, 1957 Furthermore, the inner extend somewhat further if desired. The two cups in efie'ct define an annular channel'from which the outer series of tufts extend and such outer series is accordingly better supported and maintained in proper pDsition when the tool is held forcibly against the -work The inner surface of the central cylindrical portion 9:. may bethreaded for direct attachment to a spindle or the like, or it may be of hexagonal or other noncircular contourfor: mounting ona complementary spindle. a I

Other modes of applying-the principle of the inventionomay; be ernployed, change being amade as regards the-details described, provided the features stated in any of thefollowing claims or the equivalent of such be empl y d Ltherefore particularlypoint out: and distinctly claim as mysinventionz y 1.:A:cup-brush comprisinga cup shaped annular sheetimetal-iholder havingl a generally, cylindrical outer wall and an internal cylindrical wall portion of less axial ex-' tent defining therebetween an annular channel in which the-other brush elements are adapted to be :seated and retained, the lip. of said outer wall flaring outwardly, an annular flat disc seated in such annular channel and fittingz' said internalwall portion, said disc having. a plurality, of closely spaced evenly distributed holesuthere thriough adjacent its outer periphery, tufts of wire bristle material inserted through such holes and doubled and twistedon themselves aboutthe edge'of the disc to form twisted tufts extending a substantial distance beyond said Iip-imadire'ction substantially parallelto the axis of: the brush an'inner thin sheet metal cup tightly. fitted against said disc and the inner sides of said tufts having a central openingzfittingsaid internal wall portion of said outer holder, the sidewall of said inner cup, flaring slightly,-

outw'ardlyfand extending substantially, the same distance as-isaid outer wall toward the working ends of said tufts, a spacer washer fitting said internal wall portion and engaging the bottom of said inner cup but spaced from the=sidewall cf the latter, a second disc engaging said washer and fitting said internal wall portion'bearing an" inner circumferential series of twisted tufts of brush bristle 'mate'rial in the same manner as said first disc, saidinner series of tufts extending generally parallel to the axis of the brush-and supported against the inner face w'all portionbeing-deformed to engage' said latter washer firmly to secure the entire assembly together as a unit and-the: base of said holder beint bulged adjacent its outer periphery better to accommodate the reheat portions' of said twisted tufts of said first disc.

' 2.= A cup brush comprising a cup-shapedannular sheet metalf holder having'a generally cylindrical outer wall and an=internalcylindrical wall portion of less axial extent defining therebetween an annular channel in which the other brush elements are adapted to be seated and retained, an annular flat disc seated in such annular channel and fitting said internal wall portion, said disc having a plurality of closely spaced evenly distributed holes therethrough adjacent its outer perip ery, tufts of wire bristle material inserted through such holes and doubled and twisted on themselves about-the'edge of the disc to formtwisted tufts extending a substantialdista'nce beyond said lip:in a direction substantially'parallel to the axis of the brush, an inner thin-sheet metal cup tightly fitted against said disc andthe inner sides of said tufts having a central opening fitting said internal wall portion -ofsaid-outer holder, a spacer-washer fitting said' internal wall porti'on' and engaging the bottom of saidinncr cup but s'pa'ced fromthe side wall of the latter, a second disc engaging-said wa'sher andfitting said inte'rnal wall portionbea-ri'riganainner circumferential se'r ies of twiste'dnuns-- auras-nos of brush bristle material in the same manner as said first disc, said "inner series of tuft's extending generally parallel to the axis of the brush and supported against the inner face of the side wall of said inner cup, at dished washer fitting said internal wall portion and engaging said second disc with its outer periphery bearing against said inner series of tufts; and means securing such assembly tightly together asma. unit.

3? A fcupj'brnsh comprisinga cupE'sh'ape'd annular holder having a generally cylindrical'oute'r wall' and'an internal cylindrical wall portion of less axial extent defining therebetween' anannular" channel in which'the other brushelements are adapted itoibeiseated and retained, an annular flat disc seated in such annular channel and fitting said internalwall portion, tuftsof-brush material securedwto said disc and 'extendingfa substantial distance beyond said outer wall in a directionsubstantially'parallel to the axis of the brush; an inner thin sheet metal 'cupftightly fitted against said disc .andl'the'inner sides of said'tufts' having a central opening fitting said internal wall portionh of saidouter holder, a second disc fitting said internal wall portion having tufts of brush material secured thereto and extendingj'therefrom' forming an inner series of tufts supported against'the inner face of the side wall of said 'inner cup, means internally of said inner series engaging and bracing the same against inward movement,

and-rneansse'cu'ring such assembly tightly together asa unitL" 4. I ri arota'rybrush having twisted tufts of brush ma ter'ial extendinggenerally-parallel to the axis of rotation of said brush andLar'ranged in two closely adjacent concentric inner and outer circles, and an outer annulus. closely surroundingsaid outer circle of tufts to prevent radially outward swinging rnovement' of said tufts under the influence of centrifugal 'force inoperation; another annulus interposed between said circles of tufts and closelysurrounding: said inner circle in a region at least as near the working ends of saidtufts as said outer an? nullis to prevent' excessive outward movement of said tufts of said inner circle between said-tufts of said outer circle when the brush is rotated at highspee'ds in use.

5. In a cup. brush comprising a cup-shaped outer holder having a generally cylindrical outer wall, an outer circle of twisted tufts .ofbrush material secured therein and extendinga substantial distance beyond said outer wall, and an inner circle of twisted tufts of brush materiallsecured inasaid holderwithin said'fir st circle andv extending a substantially.equalldistance generally par-. allel to the axis .ofthebrush and said tufts of saidouter circle; an annulusuiriterposed and secured between said circles of tufts and enclosing 'said'inn ercircle eifective to prevent excessive outward movement ofathe tufts of said inner circle .under the influence 0f. centrifugal force when the brush is rotatedat-high speeds in .use.

6. In a rotary brush having an outercircle of .brush material extendinggenerallyparallel t0-the axis of mmtion of said brush an outer-annular member closely encircling andfembracing: said circle of brush material to inhibit radially outwardly flaring movement thereof under the influence of centrifugal force when said brush is rotated rapidly, andan inner concentric circle of brush material extending parallel to that of said outer circle' and closelyadjacent thereto; an annular element interposed between saidcircl-es of brush material and embracing said inner circle to inhibit outward flaring movement of said brush material-of saidlinner circle into theregion of said outer circle under the influence of centrifugal force;

References Cited in thefile of this. patent UNITED STATES PATENTS- 1,339,894" Jo'h'nson' May ll, 1920 1,829,669 Merte's Oct. 17,1931 2,062,047 Bickel- .Nov. 24, 1936 2,480;8'l7 Peterson .Sept..- 6; 1949: 2,534,891 Wilhide "nus--- wDe'c. 19, 1950 

